My 06 lexus es330 leaks water from front pillar panels when rain and soaks floorboard

Four possible causes (may be more):
1. Leak at door or window/windshield (particularly after rain or car wash).
2. The heater core is leaking (water will be on the passenger side floor).
3. Blocked A/C condensation drain
4. Leaking sunroof or blocked drain (should be evidence of water on the A or B pillars, also after rain or car wash)).

Pick one ...

Check the door drain vents in the bottom of the door ensure they are not blocked, when it rains the rain travels through the door at the window seal and escapes through opening,
. Open the door and check underneath. If blocked water fills the door and gets into the car. Also if the car has a sunroof water may be coming through there. If not this try going through a car wash while in the car and seen if you can see it hear any water getting in my

If you have a sunroof it could be the drain that follows the front pillar letting out under the front fender. These hoses are known to plug and crack open releasing water into the floorboards.

Driver side door check along top and front edge for tears or twisted looses sections. Internal to the door water can drain down along the window and is released outside the door seal. If the bottom of the door has the opening that releases the water plugged then water will drain over into the floorboard.

Water leaks are fun to trace out. the drain holes and tubes can be seen with roof open and can be unplugged with compressed air . but usually the headliner is soaked and leaks on to seats the windshield will leak on to passenger floor. remove glove box and check for wetness along "A" pillar.

is it only when the ac is on? there is a pan under the ac unit that has a hole in it to allow the condensation to empty. if that hole gets plugged it could cause the condensation to build up and back into the inside of that car. i unplugged mine and floor stayed dry

If you remove the door rails at the bottom of the doors you'll be able to lift the carpet and visually look for some small drain plug devices. It sounds like one or more of them is missing or that you have lost a seal in the door or window.

try having an assistant 'water'' your car with a garden hose while you're in it.especially check seals at windshield & doors.it could take a few minutes of ''watering'' before a leak shows up.

I had a similar leak on a 1995 Accord. I traced the issue to the plastic liner behind the door panel. The seal was broken at the bottom and water would leak from that to the rubber weatherstrip at the bottom of the door that seals at the plastic threshold molding. You can't really see it good until the door panel is removed. The water would drip until it puddled up enough to run over the threshold molding and under the driver's seat. This caused the floorboard behind the driver's seat to be soaked after a rain. I have resealed the plastic lining but of course it hasn't rained since. I'm confident this will solve my problem and hopefully provide you a new place to look for yours.

do you have a sun roof, if so start there, because there are two hoses at the back corners of the roof pan that allow water to drain, if they leak, they will soak the rear floorboards, and if not that check the door jam seals.(note that if the plugs on the floor are missing that will be verry hard not to have wet carpet)........let me know?

most likely when some one replaced the windshield they did not put the self sealing riviets in that hold the trim on. remove the cover on the side of the windshield and look. if that is not it check the moon roof drain tube runs in the a pillar